High Power Electric Propulsion - Theory

Theory

The HiPEP thruster differs from earlier ion thrusters because the xenon ions are produced using a combination of microwave and magnetic fields. The ionization is achieved through a process called Electron Cyclotron Resonance (ECR). In ECR, the small number of free electrons present in the neutral gas gyrate around the static magnetic field lines. The injected microwaves' frequency is set to match this gyrofrequency and a resonance is established. Energy is transferred from the right-hand polarized portion of the microwave to the electrons. This energy is then transferred to the bulk gas/plasma via the rare - yet important - collisions between electrons and neutrals. During these collisions, electrons can be knocked free from the neutrals, forming ion-electron pairs. The process is a highly efficient means of creating a plasma in low density gases. Previously the electrons required were provided by a hollow cathode.

Read more about this topic:  High Power Electric Propulsion

Famous quotes containing the word theory:

    Every theory is a self-fulfilling prophecy that orders experience into the framework it provides.
    Ruth Hubbard (b. 1924)

    In the theory of gender I began from zero. There is no masculine power or privilege I did not covet. But slowly, step by step, decade by decade, I was forced to acknowledge that even a woman of abnormal will cannot escape her hormonal identity.
    Camille Paglia (b. 1947)

    There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.
    Albert Einstein (1879–1955)